There's always some weird noise!

[Luke]

Well, i finally get rid of that timing chain rattle, and now im faced with some other annoying noises. Not too long ago I started noticing one noise kind of like a whistle/hissing. It only happens when i give it some sort of gas, under a load, like while im driving. It doesn't do it stopped in neutral that i can tell. I can't remember totally, but i think it does it more when the car warms up some.

I would be a retard and say it sounds like a turbo, but that's what everyone does when they hear a whistle noise from their car. I have even scared some random people trying to race me on the street and i had another guy asked if i had an sr. haha anyways. I checked around for vacuum leaks real quick, and didn't see any obvious leaks.

Ok, and more recently, i've been noticing a metal rattling under the middle of my car ( i think). What's weird is, it only seems to want to vibrate at constant rpms. Moreso, when the rpms pass by either 3k rpms or 2k rpms, it will do it, and i can hold it like that for a little while, but no where in between. I got under my car and felt/looked for loose heatsheilds and found none. I'm gonna jack it up in the next couple days to get a better look. I did notice that I guess the ground wire that is by the cat is hangin there(from the top of the car, disconnected from the cat, the wire was ripped). I wonder what that has to do with anything hehe.

Anyways, does anyone think that rattle could be an exhaust leak or something? Or maybe a rotted out cat? I've only got 100k miles. And could that whistle be linked to this other noise possibly? I'm looking for some ideas that's all. I also just replaced the water pump, what kind of noises do those make when they aren't working properly (my old one was leaking, i did a good job of replacing it though). Thanks for any help...